Author: Naveed Ashraf (University of Iceland) - The electrocatalytic conversion of carbon dioxide (CO2) into valuable hydrocarbons presents significant potential for improving sustainable energy approaches. Prior experimental and theoretical investigations have demonstrated the feasibility of converting CO2 into valuable products; however, certain hurdles must be resolved to enhance its efficiency. A significant problem is identifying a catalytic material that is stable, active, and selective for CO2 capture and conversion. Consequently, we focused on investigating novel catalyst materials on 11 transition metal carbides (100) surfaces for the electrochemical reduction of CO2 and its transformation into useful products, CO, formic acid, methane, methanediol, and methanol. We assessed the potential efficacy, selectivity, and stability of diverse new materials for the synthesis of hydrocarbons or oxygenates, encompassing synthetic fuels and other carbon-derived products. Density functional theory (DFT) computations were employed to investigate the thermodynamics of the processes. Free energy diagrams were generated for CO2 adsorption and electrochemical protonation to determine the onset potential necessary for product formation on various catalyst surfaces. To illustrate the catalytic potential, limiting volcano plots for several products were created using scaling relations of adsorbed intermediates. Our findings indicate that VC is the most promising candidate for the formation of formic acid with 0V onset potential values. In addition, WC is the best candidate explored to produce methanol at an onset potential of -0.36 V, and MoC is the most promising candidate for the formation of methanediol with a -0.58 V onset potential value.
